Monitoring various biological body parameters is known. For example, diabetics find out their glucose level by pricking themselves several times per day The most common prior art involves taking body fluid samples, most commonly blood, and often sending them to a lab for analysis. Another common method is to expose test patches to a fluid sample, commonly urine. Urine testing has the advantage of not needing an invasive procedure like with blood. It has the limitation, however, of reflecting a cumulative average over hours where blood samples reflect the current state.
The prior art in regards to glucose involves puncturing the skin and collecting a small sample to be analyzed by the patient. This is an especially important case of prior art for two reasons. One reason is the number of tests performed per day is in the millions. Another important aspect of this test is that it typically needs to be and is done entirely by the patient with equipment that can be carried around in a purse or briefcase.
There are many diagnostic tools on the market with yield a visible change to indicate a condition or state of the body. Examples would include home pregnancy tests, pH strips, urine protein sticks, etc. While these are good demonstrations of instant readout of an important physiologic parameter, none of these are done as an implant.
The examples that follow include a glucose tattoo. It is based on the chemistry disclosed in U.S Pat. No. 5,342,789. In this patent there is a reference to tattooing in claim 21. It says "the method of claim 5 wherein said specific binding pair is tattooed into the skin of the individual". Claims 5 describes the relevant chemistry as being " . . . comprising of a specific binding pair which comprises a first member which is a glucose-binding ligand labeled with a first light absorbing material and a second member which is a glycoconjugate labeled with a second light absorbing material . . .". It also claims " . . . placing a sensor in communication with glucose present in the body fluids of the individual in such a way that once in place said sensor does not exit the skin of the individual . . ." Nowhere in the patent does the means to accomplish this receive attention. How to accomplish this is an aim of this patent, The idea of an implanted sensor does not necessarily mean a dermal implant. Nowhere in the patent is there discussion of making particles suitable for tattooing.
Other patents pertaining to diagnostic tattoos are U.S. Pat. No. 5,494,030, "Apparatus and Methodology for Determining Oxygen in Biological Systems", and U.S. Pat. No. 5,706,805, "Apparatus and Methodology for Determining Oxygen Tension in Biological Systems". The '805 Patent is very specific to using EPR (electron paramagnetic resonance) in conjunction with carbon particles for oximetry measurements. The '030 Patent is directed solely at oxygen tension measurements using EPR and India ink. The '805 Patent broadens these claims to include a totally non-invasive approach using India ink or lithium phthalocyanine. It also mentions measuring free radicals, pH and temperature as possibilities using their EPR techniques.
This invention will allow the implantation of a diagnostic tattoo. The said tattoo would allow for continuous, noninvasive monitoring of a wide array of relevant parameters. The benefits of this invention are numerous. They include continuous monitoring capability, virtually any analyte that is present in interstitial fluid may be monitored, once implanted, readings are non-invasive and therefore no risk of infection, are extremely simple to read and understand, immune to contamination problems associate with fluid sample containers and sample acquisition techniques, and works equally well for the unconscious.